A large variety of antiperspirant and/or deodorant formulations have been described in the patent literature and/or have been made commercially available. These products have included solids (for example, wax and gel sticks), semi-solids (for example, gels and creams), liquids (for example, roll-on products) and sprays (both aerosol and non-aerosol). In recent years a strong emphasis has been placed on improving both the performance and the aesthetics of these products. Any improvements must take into account both the form of the composition and the method of application.
With regard to emulsions, U.S. Pat. No. 4,673,570 to Soldati describes uniform, clear gelled antiperspirant compositions, free of waxes wherein the emulsions comprise in combination a volatile silicone fluid, a silicone emulsifier (such as a mixture of cyclomethicone and dimethicone copolyol), a destabilizing auxiliary emulsifier, water, a non-volatile emollient (such as C10-C20 alkyl fatty esters and ethers), linear silicone fluids, a coupling agent (such as low molecular weight alcohols and glycols), an active antiperspirant component and other ancillary agents.
U.S. Pat. No. 5,008,103 to Raleigh et al describes water-in-oil antiperspirant emulsions having a discontinuous polar phase containing water and optionally containing an emulsifier with a hydrophilic-lipophilic balance (HLB value) greater than 8, and a volatile silicone continuous phase with a dimethicone copolyol emulsifier. The HLB parameter is a well known parameter the calculation of which is disclosed and explained in numerous references. For nonionic surfactants, data obtained by actual analysis is usually a more accurate measure of HLB values (rather than theoretical determinations). For purposes of this invention it is intended that either the actual or theoretical HLB value may be used as the basis for selection. U.S. Pat. No. 5,401,870 to Raleigh et al and U.S. Pat. No. 5,292,503 to Pereira et al describe similar subject matter.
U.S. Pat. No. 5,216,033 to Pereira et al describes a transparent water-in-oil emulsion containing a silicone phase with a dimethicone copolyol and an aqueous phase containing a refractive index "transparency structurant" to produce a refractive index matched clear emulsion. The transparency structurant is a C3-C8 polyhydric alcohol.
There remained a problem with tack (stickiness), however, and attempts to create better products included removing water from the formulations. A presentation entitled "Novel Formulations Based on Nonaqueous Emulsions of Polyols in Silicones", by A. Zombeck and G. Dahms (Paper presented at the 19.sup.th IFSCC Congress, Sydney, Australia, Oct. 22-25, 1996) describes stable anhydrous antiperspirant emulsions prepared with propylene glycol; however, clear emulsions are not reported. Other parties have added ethanol but the quantities are so large that the regular emulsion (macroemulsion) is converted into a microemulsion with the result that the formulations are tacky.
U.S. Pat. No. 5,599,533 to Stepniewski et al describes the use of silicone elastomer in an aqueous water-in-oil emulsion, but does not describe a clear emulsion.
EP 0 732 273 B1 to De Laforcade describes an applicator and a viscous product for such applicator. These products are creamy or pasty or in the form of a foam. The applicator has a porous, rigid applicator element. A dome structure is used for the dispensing surface and may be made of sintered material having pores in the range of 1-500 microns which communicate with one another in all directions.
Other examples of applicators useful with gel compositions which applicators have a plurality of surfaces include U.S. Pat. Nos. 4,801,052 and 5,372,285 as exemplified in Speed Stick.RTM. and Right Guard.RTM. gel products. Yet another applicator for semisolid products utilizes a sintered plastic material called Porex that has random, nonlinear, branched pores of varying cross-sectional diameters. Pressure relief mechanisms to solve post-extrusion of product and avoid leakage of unwanted product are described in U.S. Pat. Nos. 5,540,361 and 5,547,302. U.S. Pat. No.5,547,302 also describes the use of a thin, flexible mesh with a plurality of discrete openings extending through the mesh as an applicator surface.
In a different approach, the use of an improved applicator with porous structures has been developed. This is the subject of the co-pending cases assigned to the same assignee as this application. This applicator requires a new type of formulation for a satisfactory product, in particular forming a product that minimizes leaking problems and has superior aesthetics when applied to the underarm. Previous formulations, especially including certain gels and other compositions containing thickening agents are not suitable because they do not have the desired aesthetics. On the other hand, one must be sensitive to the use of liquids in these new applicators since the liquid can ooze or drop out of the container. Separation of phases must also be prevented. Thus, there remains a need for new compositions which are suitable for use with porous top applicators which have mini-holes, pores, screen or woven applicator surfaces.
It is, therefore, an object of the present invention to provide antiperspirant and/or deodorant compositions which are suitable for use with the applicators described above. It is a further object of the invention to provide compositions suitable for use with the applicators described above which minimize problems from leaking. It is yet another object of the invention to provide formulations suitable for use with the applicators described above which minimize problems of phase separation. It is an additional object to provide formulations suitable for use with the applicators described above which are easy and convenient for the consumer to use. These and other objects will become apparent from the following description of the invention.